A Field‐Based Investigation of the Association Between Cotton Leafroll Dwarf Virus and Bronze Wilt‐Like Responses in Upland Cotton in Georgia

ABSTRACT In the United States, cotton leafroll dwarf disease (CLRDD) is a concern due to the complexity of its symptom expression and associated yield reductions. Among symptoms associated with CLRDD, bronzing and wilting have emerged as prominent host responses, exhibiting similarity with abiotic stresses and physiological disorders. This study examined the association between cotton leafroll dwarf virus (CLRDV) infection and expression of bronze wilt‐like symptoms in upland cotton by assessing symptom progression and yield outcomes across selected cultivars in on‐farm variety trials conducted in Georgia. Disease severity varied across years, locations and cultivars, having low incidence in 2022 and negligible in 2023, but a significant surge in some cultivars in 2024. Molecular assays indicated that symptomatic plants in these cultivars exhibited higher viral copy number of CLRDV coat protein gene and correspondingly no measurable yield in contrast to asymptomatic plants. Yield performance varied across the monitored locations. Notably, the yield per unit land area of some cultivars at locations of Turner and Worth County with low disease incidence exceeded the 2024 trial averages. In contrast, dryland and irrigated fields in Colquitt County, which had high disease incidence, showed yield declines, falling below trial averages. An exception was DP 2038 B3XF under irrigation in which yield per plant was reduced, but the yield per unit land area remained unaffected. The overlapping symptom expression in CLRDD and bronze wilt‐like response underscore the complex interplay between CLRDV infection, cultivar susceptibility, geographical location and environmental factors that need further investigation under controlled conditions.